What's the difference between CO2 and Compressed Air/Nitrogen/Nitro
To set the record straight, Compressed Air/Nitrogen/Nitro are essentially the same thing. Once upon a time, HPA (High Pressure Air) tanks were filled with Nitrogen as with today it is high-pressured air, using a compressor, as the name suggest. Nitrogen has just stuck with the name but very few places, if any, still use pure Nitrogen.
Now, there are two versions of CO2, standard CO2 and Anti-Syphon CO2. Standard CO2 are the tanks you will find in sports authority or what you currently find in marker packages. It is a standard metal cylinder, usually 9, 12, 16, or 20 oz in size with a valve at the end. The cylinder is filled with liquid CO2 and when it is screwed into the marker it propels the internal valves as the liquid is turned to a gas through the hose line and into the gas-thru. There is a risk of liquid CO2 going into the marker and freezing the marker, literally.
Anti-Syphon CO2 is a standard CO2 tank fitted with an anti-syphon tube, it is a small brass tube that sticks out of the valve of the tank and rests above the liquid CO2. This introduces air into the valve sooner to help promote the liquid CO2 into turning into a gas, thus reducing the chance of a freeze though it does not eliminate the threat entirely.Should I get CO2 or HPA for my marker?
First thing to do is ask yourself, 'What are my needs?'. Are you a rec player with your friends in the woods? Do you enjoy casual play at your local field from time to time? Are you hardcore woodsball? Do you have hopes and dreams of playing in the NPPL?
If you are just playing around with friends I would suggest standard CO2 as it is the most cost effective. Though, if you have the money Anti-Syphon couldn't hurt as you will get slightly better marker performance. More on that later.
Even with casual field play, it may be best to get an Anti-Syphon CO2 tank. Slightly better performance over standard CO2 without some of the hassle but still quite affordable.
For the hardcore woodsballer, I suggest Anti-Syphon CO2 once again though a metal HPA tank can be purchased for 70-80 dollars and take more of a hit then a fiber wrapped HPA tank would. The HPA I would recommend for only those who definately plan to stay in the sport for a while, not an impulse purchase to see if you'll like it. Though the HPA will give you a cleaner running marker and better performance, this is definately more for somebody that is quite into the sport.
Now, for those of you hoping for NPPL glory I would really only suggest HPA. It's more effecient then CO2 in every aspect. There is no risk of freezing as it is air temperature, it will hold more shots then CO2, it will not spike like CO2, and it will not destroy your solenoid valve as most, if not all, electronic markers now use one. You can purchase a metal tank for 70-80 dollars as I mentioned before but these are heavy and Speedball players need a lighter tank so you will need a fiber wrapped tank. These are lighter but usually require a tank cover to protect it from any damage on the field and cost around 200 dollars on average for a good one.That's well and good but I still don't get the performance differences between CO2 and HPA and what I need.
This is a rather in depth topic and I felt I needed to split it up into smaller sub-categories. As I said you first need to establish your needs as a player, done with that? Good. Onto Air 101.
CO2 is a liquid, it is the liquid form of what you exhale and is by nature cold. CO2 can and will turn to ice if you rapid fire for too long and has velocity spikes because of it's cold temperature. This means if you chrono (the speed of the paintball leaving your marker) at 250 FPS with CO2 you may suddenly shoot 190 then spike it to 320 fps, I've seen it happen. CO2 isn't the most stable thing to use as far as velocity because it's constantly warming up when you're not firing and then rapidly cooling when you're firing. An Anti-Syphon tank can help reduce this but ultimately to completely get rid of this problem you need HPA. Though, Anti-Syphon tanks will help with reducing the chance of liquid CO2 entering your marker and causing spikes it will have no effect on helping with spikes associated with the cooling of the CO2 during rapid firing.
HPA is more stable because it will retain the air temperature around it and can also be regulated since it is essentially just compressed air. The air will leave the tank through the tank reg, either a preset High-Pressure, Low-Pressure, or Adjustable, enter the air line and go into the HPR, (High-Pressure Reg), which will then adjust the pressure to something lower that the marker will use to cycle and then the air enters the LPR (Low pressure regulator). This adjusts the marker to a psi even lower then the HPR. Any spiking that may be encountered is usually attributed to the HPR or LPR needing cleaning or just fluxing as some are better then others. The HPR fluxing will affect velocity while the LPR will affect the markers cycling ability. Also, HPA tanks are generally more expensive then CO2 tanks but the performance differences are gigantic.
So in conclusion HPA will have a better overall performance as it will not spike as much and will not get cold like CO2 will. Unless your playing in the middle of winter, waist deep in snow, with your skin turning blue... at that point you're a more hardcore paintballer then I ever will be. Though the price differences are large to most people, HPA will run cleaner in your marker, provide better effeciency, and will give you a time playing as your balls won't be dropping off like the people using CO2.Okay, I want HPA now because CO2 is the newbie devil gas... but what's HP and LP?
HP is High Pressure, LP is Low Pressure. Simple enough, right? Wrong.
First you need to establish what your marker can run. Please note that a good 99% of markers that are labeled as Low-Pressure Markers CAN run HP air. Low-Pressure Markers are usually referring to the operating pressure, meaning that it will operate around 200-400 psi, depending on the year and model of the marker. The newer markers will have a lower operating psi because of the new technology with the valve systems. Do the research and ask intelligent questions. Note I said intelligent.
Now, an HP tank will output from 800-850 psi depending on the manufacturer and LP will output at 400-450 psi. The more common out puts are 400 and 800 though.
For an example, I am currently using a 2k2 Dragon Intimidator. This is considered a Low-Pressure Marker but I use an HP (800 psi) tank. How does this work? Remember the part about the regs I mentioned earlier? Now, my tank outputs at 800 psi and my HPR will knock down the psi to 200 psi so the marker can cycle properly and then the LPR will knock the psi down to 70-75 psi for Intimidators once it's adjusted. Remember, the HPR and LPR need to be manually adjusted they're not going to be magically set at those settings and keep in mind this is just for Intimidators as an example.
Now, the marker operates at 200 psi but my tank outputs 800 psi, so why wouldn't I use the LP tank at 400 psi since I would only drop 200 psi versus 600 psi?
That is something else and is called shoot-down. That accursed event in which the marker pressure drops too low and the paintball will just lob out ten feet or roll out of the barrel. Everytime you fire the tank has to recharge the air pressure. The general rule is to use a tank that is 200 psi above the operating pressure but some people, like myself, use an HP tank instead of an LP tank because the chance of shoot-down is virtually non-exsistant.
Why do you ask? Because if my tank is outputting 400 psi and my marker is operating at 200 psi then I start rapid firing my tank pressure can drop to 375, 350, 300 psi before it can fully recharge. Meaning my shots are falling shorter and shorter. Now if I use HP my pressure can drop to 775, 750, 725 and it will not affect my shots what so ever.
Once again, check to make sure what your marker can run before you just slap a tank onto it. Some Angels for instance are recommended for LP use only but can use HP, still WDP recommends LP for them. Better to be safe and just check as too much pressure in certain markers can blow airlines and solenoids valves.Metal or Fiber wrapped tanks?
This is quite simple, I recommend metal tanks for woodsball players because a metal tank will more then likely just scratch when hitting a rock while a fiber wrapped tank would probably go off like a small bomb if it hit a rock. Metal tanks are heavier, cheaper, and are HP (800 psi) but I believe there are some LP ones, though there are probably LP ones out there as well.
Fiber wrapped tanks are lighter, more expensive and come either HP, LP, or Adjustable. For those of you wondering I wouldn't bother with Adjustable tanks until you are an experienced player, even then I have yet to see somebody using an adjustable; which is why I hardly mentioned it. A preset HP or LP will do you fine. A bottle cover is a must for these guys as they will scratch and break easily since they are just fiber wrap and glass essentially. I would recommend this for all speedball players as a steel tank will just weigh you down when you need to sprint to a bunker.
Also, it depends on how much you have and once again comes to style of play as I mentioned above. For my style I will pay the extra and get the fiber wrapped tanks but ultimately it is up to you.

What's 45 ci? And what the heck is the difference between 3000 psi and 4500 psi?
A number ending in 'ci' is the size of the tank, it means 'Cubic Inches'. This is the physical space and ultimately size of the tank/bottle and only refers to HPA systems.
3000 and 4500 psi refers to the pressure rating. This means that the tank can either be filled up to 3000 psi or 4500 psi. This will affect how many shots you will get out of a tank. A 45 ci tank at 3000 psi will get fewer shots then a 45 ci 4500 psi tank because there is 1500 psi less in the 3000 tank compared to a 4500 tank. Whether you get 3000 or 4500 is up to you.
Very quickly on sizes, there is a 45, 68, 70, 72, 88, and 92 respectiably. There are some odd ball sizes out there but those are the most common sizes you will see. Please note that the 72 ci size is more common for metal tanks, not carbon fiber tanks.
When you put these numbers together you get something like this, 45/4500. This means 45 cubic inches and 4500 psi capacity. Now when shopping for one you will see HP 45/4500 or LP 45/4500. What does this mean? Hopefully you've been paying attention. One is an HP (800 psi output) tank at 45 cubic inches and 4500 psi capacity while the other is LP (400 psi output).
And for the love of Paintball, these sizes don't mean that with an HP tank you're only getting 4 shots out of a 3000 psi tank because you're using 800 psi per shot; I know somebody is thinking that. It just doesn't work that way.Alright, I get it now but what's the BEST tank out there?
In my opinion, along with others, Crossfire, Macdev, and Centerflag in that order. Why? Those three companies have excellent safety records for one and have high manufacturing standards and quick recharge rates.
Remember you are dealing with air that is compressed to 3000-4500 POUNDS PER SQUARE INCH. Now if you paid attention in math if you take a cube that is one inch by one inch there is 3000-4500 psi in the one little space and there is 45-92 cubic inches in a tank depending on what one you have. I can not stress that enough so you maintain your equipment properly and safely.
But back to those three tanks, all make tanks around 200 dollars and have some of the best recharges rates meaning you won't suffer from shoot-down as much if at all because the air pressure will go back to normal more quickly. Macdev is rated at 8ms, Crossfire at 10-12 ms, and Centerflag is 14 ms.
Now, I know that Java, Pure Energy, and other companies make fiber wrapped tanks for cheaper but that is the key word... Cheaper. It's not to say they are bad tanks it's just that their recharges for one are much less then the other three I mentioned and I personally feel that they are not built to the same standards as Macdev, Centerflag, or Crossfire. I know all tanks have to meet specific regulations to pass but Macdev, Centerflag, and Crossfire all surpass those standards so just in case one is sub-par for them it will still pass those regulation tests.
I would rather pay the extra money for a tank that I know is going to be safe and effecient rather then take a chance on something that may be subpar. That's the way I feel about and that's what I'm sticking too. If I had a 150 bucks in my pocket and couldn't afford the 200 dollar tank... I would take a metal crossfire over a fiber wrapped Java or Pure Energy.Please keep in mind that the basis of which tank brand is preference and if you think I 'bashed' a brand because I said it's cheaper is based solely on my own PERSONAL preference. Just keep in mind safety first and I will be content.I absorbed the knowledge like a sponge and understand the differences of CO2 and HPA. Now I am set on an HPA tank, I know the size I want, whether I want metal or fiber wrapped, what brand, and I know if I need HP or LP. But should I get a drop forward or rail on/off?
This is probably one of the most asked questions next to 'what tank is the best'. This is based solely on personally preference but there are a few things to keep in mind.
A drop forward will add height to the marker while a rail will add some length you will get a tighter, smaller profile with a rail. I am not going to comment on dropforwards since I don't use them but I will say read the review boards on drops and ask around, even see what the pros are using if they are using them.
Rail on/offs are quite simple in how they operate, they are mounted on the bottom of the grip frame and you screw in your tank to the on/off. There is a knob on the end that screws in and out, when screwed in it depresses the valve pin on the tank and allows air into the marker. When turned out, it released the valve and allows it to seal cutting off the air supply to the marker. If you screw it out further, the bleed hole comes into play as it will release all the air stored into the marker and degass it. Simple enough. Just don't screw the knob in too far or you risk damaging your valve pin, screw it in until you hear the marker gas up and then give it a half to full turn more to ensure that it won't back out and you won't have air while in the middle of a game.
Now with rail on/offs there are two recommendations. The New Designz (NDZ) on/off ultra lite combo or a Custom Products (CP) on/off rail.
I personally use the NDZ on/off ultra lite combo. This is the on/off where you screw in the tank and a rail to mount it onto your marker. NDZ makes superior quality products that are durable, affordable, look nice in my opinion, and are just over all well designed products. The ultra lite only differs from the regular on/off in the weight aspect. Both have an on/off knob with a bleed hold, have dovetail mounts, and the combo comes with a rail as I said before.
The CP on/off is similiar to the NDZ on/off but the only difference is, milling/style, company, and potentially price. CP makes superior products as well and has excellent customer support. In a choice between the NDZ and CP on/off I would choose the NDZ only because I have used it and I hardly notice the weight on my marker. It's up to you what you ultimately put on.
Though I would recommend staying away from Unimounts as any repairs that you may have to do will involve you removing your macroline and elbow to remove the unimount from it's cage. Best to just stay away from them as they are a hassle.

Hopefully this clears up alot of question people may have. I offer Uziel and other mods to add to this or edit as they see fit; hopefully this may become a sticky that people will actually read. I also apologize for mistakes in grammar, spelling, and anything else as this got rather tiring after a while.